Can breast pain when using Slinda be irregular and can it happen?

Good morning, I'm on 3 blisters of Slinda contraceptive pills. At the first package, I experienced breast pain as before menstruation, which subsided after a few days. At the second, the pain did not occur at all, which made me very happy, at the third blister there was also no withdrawal bleeding, only slight sting. Today I am after 8 tablet from the third blister and again I feel breast pain. Of course, I start to suspect pregnancy (although the tablets are taken regularly and I do not take medications or other substances that can cause a decrease in the effect) because the last ratio took place with placebo tablets more than a week ago. My question is, can breast pain be irregular and can happen? Is there a risk of ovulation when taking or immediately after placebo tablets, even though they were all taken at regular times?